Dealing with the Estimation Fallacy
We've all been on projects which have delivered late. Why is that? Poor requirements, lazy staff, unreasonable deadlines?
How about that humans are inherently useless at estimating?
Estimation has been a personal interest of mine for the last 6 months or so. I'd like to present some of the things I discovered in this time in a short presentation, which would be followed by a goldfish bowl discussion.
The objective of the session is to present insight into why we are so bad at estimating and then discuss, as a group, what we can do about it.
Here's the output from the discussion:
How do you keep the context stable?
The problem is managing the context. If the business says you need to do it sooner that changes the context.
What about if the business doesn't have the full context? What about issues you don't know about?
Why are we different to any other type of organisation?
It's too difficult to estimate more than 2 months ahead
Familiar work is easy to estimate, the unknown is not (which is mainly what we do)
If we report back to the business regularly they can't deny hard facts
Manage the risk by working iteratively
It's quite common for people to start building skyscrapers before the architects finish designing the top
- but their customers not going to ask for another 20 floors and more space halfway through
We need to help the customer understand what they need
People need to know whether it's a viable business case
Projects are never agile if you have requirements up front (fine if nothing changes though)
You should only commit to work three months ahead
"2 years" for a software project is too long - will not be competitive
Movies spend a long time in development, then they get the budget and the scope gets cut to fit. But, they are more predictable than software.
Too much money (e.g. banks) will never produce good software - scope to big.
Are big estimates/commitments ever believed by anyone? Often they're only used to make projects viable
IT departments are not pushing back enough - should never suggest you can plan more than 3 months in advance
2 types of estimation:
- The real business of estimation (e.g. stories, iteration scope, tasks ect)
- The game of estimating within the business context
- Check it writing services
Agile projects are rarely ever really agile as they're operating withing the context of the business/traditional practices.
Read more on my thoughts in the articles on my blog tagged estimation or you can check out my delicious tags
Back to Open Space Topics